Complex Systems and Multiple Levels of Abstraction

M.M. Rene van Paassen (Delft University of Technology)

Abstract

Complex heterogeneous systems, such as power plants or petro-chemical process plants, nowadays contain complex automation for realising mode changes in the systems, for example for start-up and shut down. To provide support for the operators, support systems that give advice and explanation are often added. Development of those support systems is usually based on the (episodic) knowledge of expert operators, and it is difficult to design such systems so that they can cope unforeseen and unforeseeable events.

The problem is that the terms in which these systems are currently understood and described does not provide a basis for development of more flexible automation and operator support. A better perspective is offered by novel modelling paradigms, commonly named Functional Modelling, of which Multilevel Flow Modelling, the Abstraction Hierarchy or the Goal Tree, Succes Tree are examples. Application of these techniques produces descriptions that can be used to reason about goal achievement of the system~\cite{paassen:97f}.

In the presentation an Abstraction Hierarchy for a simple system is presented. Reasoning on the basis of the AH, and the use of the AH for interface design \cite{vicente:90} is discussed.